Tape head with thin tape bearing surface coating

ABSTRACT

A tape head is provided for use with a tape drive that is configured to receive a length of tape. The tape head includes a head body including at least one head element for performing read and/or write operations on the tape, and a protective layer extending over at least a portion of the head body for inhibiting wear of the head body when the tape is moved with respect to the head body. Furthermore, the protective layer is made of titanium oxide, chromium oxide, zirconium oxide, aluminum oxide, or zinc oxide.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a divisional of U.S. application Ser. No. 14/645,551filed Mar. 12, 2015, the disclosure of which is hereby incorporated inits entirety by reference herein.

TECHNICAL FIELD

The present disclosure relates to the field of tape heads used forperforming read and/or write operations on tape.

BACKGROUND

A tape drive used in magnetic tape applications may be provided with oneor more magnetic tape heads that each include one or more head elements,e.g., thin film magnetic transducers, for performing read and/or writeoperations on a magnetic tape. For each tape head, the one or more headelements are typically fabricated on a substrate and covered with a topclosure. A thick overcoat layer of alumina is also typically depositedbetween the head elements and the top closure.

During operation of the tape drive, the tape may be biased against theface of the tape head or heads as the tape is moved longitudinallyrelative to the heads. Rubbing between the tape and the tape heads maycause both items to wear. The substrates and closures of the tape headsare fabricated from hard materials to help minimize their wear. The headelements and associated overcoat layers, on the other hand, arefabricated from materials selected primarily for their magnetic andelectrical properties, and may be softer than the substrates andclosures.

The difference in hardness between the substrate and closure materials,on the one hand, and the head element and overcoat layer materials, onthe other hand, may result in uneven wear at the face of the tape headdue to contact with the tape. Because the head element and overcoatlayer materials may be softer than the substrate and closure materials,the head element and overcoat layers may recess more quickly from thetape-head interface than do the substrate and closure. As a result, aconcave shaped gap may develop over time between the head elements andthe tape. This gap may cause poor read and write performance, and eventotal failure of the tape heads in severe recession cases.

A prior attempt to reduce wear of a tape head involved coating the tapehead with a first layer of non-conductive silicon nitride, and a secondlayer of titanium applied over the layer of silicon nitride. Titaniumhas good wear characteristics, but it is conductive. As a result, thenon-conductive silicon nitride layer is provided as an isolation layerbetween the tape head and the titanium layer.

SUMMARY

A tape head, according to the present disclosure, is provided for usewith a tape drive that is configured to receive a length of tape. Thetape head includes a head body including at least one head element forperforming read and/or write operations on the tape, and a protectivelayer extending over at least a portion of the head body for inhibitingwear of the head body when the tape is moved with respect to the headbody, the protective layer being made of titanium oxide.

A tape drive, according to the present disclosure, for use with tape isalso provided. The tape drive includes a drive body, and a tape headsupported on the drive body. The tape head includes a head bodyincluding at least one head element for performing read and/or writeoperations on the tape, and a protective layer extending over at least aportion of the head body for inhibiting wear of the head body when thetape is moved with respect to the head body, the protective layer beingmade of titanium oxide.

A tape head, according to another aspect of the disclosure, is alsoprovided for a tape drive that is configured to receive a length oftape. The tape head includes a head body including at least one headelement for performing read and/or write operations on the tape, and aprotective layer extending over at least a portion of the head body forinhibiting wear of the head body when the tape is moved with respect tothe head body. The protective layer is made of a layer of titanium,chromium, zirconium, aluminum, or zinc that is deposited on the at leasta portion of the head body and subsequently oxidized to form titaniumoxide, chromium oxide, zirconium oxide, aluminum oxide, or zinc oxide.

In addition, a tape drive according to another aspect of the disclosureis provided for use with tape. The tape drive includes a drive body, anda tape head supported on the drive body. The tape head includes a headbody including at least one head element for performing read and/orwrite operations on the tape, and a protective layer extending over atleast a portion of the head body for inhibiting wear of the head bodywhen the tape is moved with respect to the head body. The protectivelayer is made of a layer of titanium, chromium, zirconium, aluminum, orzinc that is deposited on the at least a portion of the head body andsubsequently oxidized to form titanium oxide, chromium oxide, zirconiumoxide, aluminum oxide, or zinc oxide.

While exemplary embodiments are illustrated and disclosed, suchdisclosure should not be construed to limit the claims. It isanticipated that various modifications and alternative designs may bemade without departing from the scope of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a plan view of a tape drive including multiple tape headsaccording to the present disclosure;

FIG. 2 is an enlarged fragmentary cross-sectional view of one of thetape heads shown in FIG. 1, wherein the tape head includes a head bodyand a protective coating or layer disposed at least partially;

FIG. 3 is a fragmentary side view of the tape head shown in FIG. 2, withthe protective layer removed to show the underlying portion of the tapehead;

FIG. 4 is an enlarged fragmentary cross sectional view of the tape headsimilar to FIG. 2, after a wear test was performed on the tape head; and

FIG. 5 shows a tape head provided without a protective coating or layerand after a wear test was performed on the tape head.

DETAILED DESCRIPTION

As required, detailed embodiments are disclosed herein. It is to beunderstood, however, that the disclosed embodiments are merely exemplaryand that various and alternative forms may be employed. The figures arenot necessarily to scale. Some features may be exaggerated or minimizedto show details of particular components. Therefore, specific structuraland functional details disclosed herein are not to be interpreted aslimiting, but merely as a representative basis for teaching one skilledin the art.

FIG. 1 shows a data storage device in the form of a tape drive 10,according to the present disclosure, for use with a tape 12, such as amagnetic tape or optical tape. While the tape 12 may be provided in anysuitable manner, in the illustrated embodiment, the tape 12 is providedby a cartridge reel 14 of a tape cartridge 16 that is insertable intoand removable from the tape drive 10. The tape drive 10 shown in FIG. 1includes a drive chassis or body 18 configured to receive the tapecartridge 16, a tape guide arrangement 20 including one or more tapeguides 22 (e.g., tape guide rollers and/or fixed taped guides) mountedon the drive body 18 for guiding the tape 12 along a tape path 24 to atake-up reel 26, and one or more heads 28, such as magnetic heads oroptical heads or pick-up units, for reading data from and/or writingdata to the tape 12 as the tape 12 is moved over or adjacent to theheads 28.

Referring to FIG. 2, an enlarged fragmentary cross-sectional view of oneof the tape heads 28 is shown in order to explain further details of thetape head 28, which details may also apply to any other tape head 28provided with the tape drive 10. The tape head 28 shown in FIG. 2 is amagnetic tape head and includes a head body 29 having a device region 30positioned between two head bulk material regions or sections, such as asubstrate 32 and a closure 34. The device region 30 may include one ormore head sensors or elements 36 (e.g., transducers) shown schematicallyin FIGS. 2 and 3, as well as any other suitable layers or materials,such as overcoat layers and/or insulating layers that may be made of anysuitable material (e.g., alumina). The head elements 36 may be readand/or write elements for performing read and/or write operations on thetape 12.

The device region 30 shown in FIG. 3 includes three head elements 36 forillustration purposes (e.g., one read element and two write elements).The device region 30 may, however, be provided with any suitable numberof head elements 36 (e.g., any suitable number of read elements and/orany suitable number of write elements). For example, the device region30 may be provided with 10 to 100 head elements 36. As a more specificexample, the device region 30 may be provided with 52 read elements or32 write elements and 2 read elements. As another more specific example,the device region 30 may be provided with 34 read elements or 32 writeelements and 2 read elements. In yet another embodiment, the deviceregion 30 may include one or more head elements 36 that are each formedas a combined read-write element. Furthermore, the head elements 36 maybe arranged in any suitable orientation. For example, the device region30 may include read and write elements that alternate with each other,or similar head elements 36 may be arranged in groups (e.g., a group ofmultiple read elements may be followed by a group of multiple writeelements).

As further shown in FIG. 2, the tape head 28 is provided with aprotective coating or layer 38 that extends over at least a portion ofthe head body 29 (e.g., at least partially over the device region 30)for inhibiting wear of the head body 29 when the tape 12 is moved withrespect to the head body 29. For example, the protective layer 38 mayinitially be applied over the entire surface (e.g., face or tape-headinterface) of the head body 29, or substantially over the entire surfaceof the head body 29 (e.g., greater than 90% of the head body), such thatthe protective layer 38 is located between the head body 29 and the tape12 when the tape 12 is moved over the tape head 28. In the embodimentshown in FIG. 2, the protective layer 38 is disposed directly on thedevice region 30, substrate 32 and closure 34. Furthermore, theprotective layer 38 may extend entirely, or substantially entirely, overa surface 40 (e.g., face or tape-head interface) of the device region30, as well as entirely, or substantially entirely, over correspondingsurfaces (e.g., faces or tape-head interfaces) of the substrate 32 andclosure 34.

The protective layer 38 may be made of a material selected from thegroup consisting of titanium oxide, chromium oxide, zirconium oxide,aluminum oxide and zinc oxide. Furthermore, the protective layer 38 maybe formed in any suitable manner (e.g., by any suitable method). Forexample, after the head body 28 has been fabricated in any suitablemanner, a layer of titanium oxide, chromium oxide, zirconium oxide,aluminum oxide, or zinc oxide may be applied directly on the head body29 by any suitable application technique. As a more detailed example, alayer of any of the above materials may be applied by one or more ofsputtering, atomic layer deposition (ALD), chemical vapor deposition(CVD), or pulsed laser deposition (PLD). Because each of the abovematerials is electrically non-conductive, no isolation layer is neededbetween the head body 29 and the protective layer 38.

As another example, a layer of material selected from the groupconsisting of titanium, chromium, zirconium, aluminum and zinc may beapplied directly on the head body 29 in any suitable manner, and thenthe layer of material may be oxidized in any suitable manner to form theprotective layer 38, such that the protective layer 38 is made of aselected one of titanium oxide, chromium oxide, zirconium oxide,aluminum oxide, or zinc oxide. As a more detailed example, a layer oftitanium, chromium, zirconium, aluminum, or zinc may be applied by oneor more of the above application techniques, and then the layer may beoxidized by exposing the layer to an oxygen environment (e.g., oxygengas, or gas mixture including oxygen) at an elevated temperature (e.g.,temperature in the range of 50° C. to 150° C.) so that the entirethickness of the layer is oxidized to form the protective layer 38.Exposing the layer to an oxygen environment may include positioning thetape head 28 in a container (e.g., chamber or oven), and thenintroducing oxygen gas or gas mixture including oxygen through a gasline into the container. Furthermore, if the oxygen environment includesa gas mixture, the percent of oxygen may be at least 20% of the gasmixture, or at least 50% of the gas mixture, for example.

As another more detailed example, the layer of titanium, chromium,zirconium, aluminum, or zinc may be exposed to an oxygen plasma to formthe layer of titanium oxide, chromium oxide, zirconium oxide, aluminumoxide, or zinc oxide. Furthermore, such exposure may occur at anysuitable temperature, such as a temperature in the range of 50° C. to300° C., or a temperature in the range of 50° C. to 150° C. The oxygenplasma can be created or formed in any suitable manner, such as byheating oxygen gas or subjecting it to a strong electromagnetic fieldapplied with a laser or microwave to create positive or negative chargedparticles (i.e., ions). As another example, the oxygen plasma may becreated by exposing oxygen gas at a low pressure (e.g., under a vacuum)to high power radio waves.

The protective layer 38 may also have any suitable thickness. Forexample, the protective layer 38 may have a thickness in the range of 4to 25 nanometers (nm). In one embodiment, the protective layer 38 mayhave a thickness less than 20 nm. In another embodiment, the protectivelayer 38 may have a thickness less than 15 nm. In yet anotherembodiment, the protective layer 38 may have a thickness less than 10nm.

If the protective layer 38 is formed by first applying a layer ofmaterial selected from titanium, chromium, zirconium, aluminum, or zincto the head body 29 and then oxidizing the layer of material, thethickness of the layer of material may be less than the above values,since the layer of material may expand during the oxidizing step. Forexample, the layer of material deposited on the head body 29 may have athickness in the range of 2 to 20 nm. In one embodiment, the layer ofmaterial may have a thickness less than 15 nm. In another embodiment,the layer of material may have a thickness less than 10 nm. In yetanother embodiment, the layer of material may have a thickness less than6 nm. Thus, the steps of applying the layer of material and oxidizingthe layer of material may be performed such that the resultingprotective layer 38 (e.g., layer of titanium oxide, chromium oxide,zirconium oxide, aluminum oxide, or zinc oxide) has a thickness in therange of 4 to 25 nm, or less than 20 nm, or less than 15 nm, or lessthan 10 nm.

As mentioned above, the protective layer 38 may inhibit or prevent wearof the head body 29, and specifically the device region 30, when thetape 12 is moved over the tape head 28 and contacts the tape head 28. Inthe embodiment shown in FIG. 4, for example, the protective layer 38(which is made of titanium oxide in this embodiment) remained largelyintact over the device region 30 after a wear test was performed inwhich the tape 12 was moved over the tape head 28 for 2,100 hours at aspeed of 5.6 meters/second (i.e., the tape head 28 was subjected tomillions of meters of tape 12). Because the protective layer 38 mayinhibit or prevent erosion of the head elements 36 and correspondingovercoat layers of the device region 30, accuracy of read and/or writeoperations performed by the tape head 28 may be maintained, and life ofthe tape head 28 may be significantly increased compared to prior tapeheads.

Furthermore, because the protective layer 38 is electricallynon-conductive, as mentioned above, the overall thickness of theprotective layer 38 may be reduced compared to prior coatings thatinclude a wear protection layer and an isolation layer positionedbetween a head body and the wear protection layer. As a result, magneticspacing between the surface 40 of the device region 30 and the tape 12may be reduced compared to prior tape heads. In addition, due toisolation improvement, yield loss may be reduced by about 6% compared toprior coatings that include a conductive layer.

In the embodiment shown in FIG. 4, the portion of the protective layer38 disposed on the substrate 32 and closure 34 has eroded more than theportion of the protective layer 38 disposed on the device region 30after the wear test. This may be due to better adhesion between theprotective layer 38 and the device region 30, as compared to adhesionbetween the protective layer 38 and each of the substrate 32 and closure34. For example, the protective layer 38 may bond better to the material(e.g., alumina) of the device region 30, as compared to the material(e.g., aluminum titanium carbon) of the substrate 32 and closure 34.

For comparison purposes, FIG. 5 shows a tape head 28′ provided without aprotective layer 38 and after a wear test, similar to the wear testdescribed above, was performed on the tape head 28′. As shown in FIG. 5,device region 30′ has eroded significantly, such that a relatively largegap exists between a surface 40′ (e.g., face or tape-head interface) ofthe device region 30′. That gap may adversely affect read and/or writeoperations performed by the tape head 28′.

While exemplary embodiments are described above, it is not intended thatthese embodiments describe all possible forms of the invention. Rather,the words used in the specification are words of description rather thanlimitation, and it is understood that various changes may be madewithout departing from the spirit and scope of the invention.Additionally, the features of various implementing embodiments may becombined to form further embodiments of the invention.

What is claimed is:
 1. A tape head for a tape drive that is configuredto receive a length of tape, the tape head comprising: a head bodyincluding at least one head element for performing read and/or writeoperations on the tape; and a protective layer extending over at least aportion of the head body for inhibiting wear of the head body when thetape is moved with respect to the head body, the protective layer beingmade of titanium oxide.
 2. The tape head of claim 1 wherein the headbody includes a device region positioned between two head bulk materialregions, the device region comprises the at least one head element, andthe protective layer extends at least partially over the device region.3. The tape head of claim 2 wherein the protective layer is disposeddirectly on the device region.
 4. The tape head of claim 2 wherein theprotective layer has a thickness less than 20 nanometers.
 5. The tapehead of claim 4 wherein the protective layer is disposed directly on thedevice region.
 6. The tape head of claim 1 wherein the protective layeris made of a layer of titanium that is deposited on the at least aportion of the head body and subsequently oxidized to form titaniumoxide.
 7. A tape drive for use with tape, the tape drive comprising: adrive body; and a tape head according to claim 1 supported on the drivebody.
 8. The tape drive of claim 7 wherein the head body includes adevice region positioned between two head bulk material regions, thedevice region comprises the at least one head element, and theprotective layer extends at least partially over the device region. 9.The tape drive of claim 8 wherein the protective layer is disposeddirectly on the device region.
 10. The tape drive of claim 9 wherein theprotective layer has a thickness less than 20 nanometers.
 11. A tapehead for a tape drive that is configured to receive a length of tape,the tape head comprising: a head body including at least one headelement for performing read and/or write operations on the tape; and aprotective layer extending over at least a portion of the head body forinhibiting wear of the head body when the tape is moved with respect tothe head body, the protective layer being made of a layer of titanium,chromium, zirconium, aluminum, or zinc that is deposited on the at leasta portion of the head body and subsequently oxidized to form titaniumoxide, chromium oxide, zirconium oxide, aluminum oxide, or zinc oxide.12. The tape head of claim 11 wherein the head body includes a deviceregion positioned between two head bulk material regions, the deviceregion comprises the at least one head element, and the protective layerextends at least partially over the device region.
 13. The tape head ofclaim 12 wherein the protective layer is disposed directly on the deviceregion.
 14. The tape head of claim 12 wherein the protective layer has athickness less than 20 nanometers.
 15. The tape head of claim 12 whereinthe protective layer has a thickness less than 10 nanometers.
 16. Thetape head of claim 11 wherein the protective layer is made of a layer oftitanium that is deposited on the at least a portion of the head bodyand subsequently oxidized to form titanium oxide.
 17. A tape drive foruse with tape, the tape drive comprising: a drive body; and a tape headaccording to claim 11 supported on the drive body.
 18. The tape drive ofclaim 17 wherein the head body includes a device region positionedbetween two head bulk material regions, the device region comprises theat least one head element, and the protective layer extends at leastpartially over the device region.
 19. The tape drive of claim 18 whereinthe protective layer is disposed directly on the device region.
 20. Thetape drive of claim 19 wherein the protective layer has a thickness lessthan 20 nanometers.